TECHNICAL FIELD
[0001] The present invention relates to an oil separator that separates oil contained in
air that has passed through equipment.
BACKGROUND ART
[0002] Vehicles such as trucks, buses, and construction machines utilize compressed air
delivered by a compressor, which is directly connected to the engine, to control systems
such as brakes and suspensions. The compressed air contains water, which is contained
in the atmosphere, and oil for lubricating the inside of the compressor. When the
compressed air containing such water and oil enters inside the systems, it causes
rust and swelling of rubber members (such as O-rings) and results in an operational
defect. Thus, an air dryer is provided downstream of the compressor in an air system
for removing water and oil from the compressed air (for example, Patent Document 1).
[0003] A filter and a desiccant such as silica gel and zeolite are provided in the air dryer.
[0004] The air dryer performs dehumidification to remove water from compressed air and regeneration
to regenerate the desiccant by removing the water adsorbed by the desiccant and discharging
it to the outside.
[0005] The air discharged from the air dryer during regeneration of the desiccant contains
oil together with water. Considering the burden on the environment, an oil separator
may be provided downstream of the compressor in the air system.
[0006] Some oil separators perform gas/liquid separation by allowing air that contains water
and oil to strike impingement members provided in the housing to recover the oil from
the air and discharge cleaned air (for example, Patent Document 2).
PRIOR ART DOCUMENTS
Patent Documents
[0007]
Patent Document 1: Japanese Laid-Open Patent Publication No. 10-296038
Patent Document 2: Japanese Laid-Open Patent Publication No. 2008-2377
SUMMARY OF THE INVENTION
Problems that the Invention is to Solve
[0008] Installation of an oil separator in an air dryer requires a space for installing
the air dryer and the oil separator. Particularly, the vertical height of such an
installation space has been desired to be reduced.
[0009] Accordingly, it is an objective of the present invention to provide an oil separator
that reduces the vertical height of installation space for an air dryer and an oil
separator. Means for Solving the Problems
[0010] To achieve the foregoing objective and in accordance with one aspect of the present
invention, an oil separator is provided that includes a housing including an inlet
for air and an outlet for air, an expansion chamber, which is located in the housing
and expands air that has been introduced through the inlet, an accommodation member,
which is located in the housing and communicates with the expansion chamber in the
vertical direction, and a collected liquid storage portion. The accommodation member
accommodates an impingement member. The collected liquid storage portion is located
below the accommodation member. The oil separator introduces air containing oil from
an air dryer into the housing through the inlet and causes the air to strike the impingement
member to separate oil from the introduced air, thereby recovering the oil. The inlet
and the outlet are located in an upper section of the housing. The oil separator further
includes a connecting hose having an oil separator connection end for being connected
to the inlet and an air dryer connection end for being connected to a purge air outlet,
which discharges purge air from the air dryer. The connecting hose is configured such
that when the connecting hose connects the inlet to the purge air outlet, the oil
separator connection end is located at a position higher than the air dryer connection
end in the vertical direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
Fig. 1 is a block diagram illustrating an installation position of an oil separator
in an air system according to one embodiment of the present invention;
Fig. 2 is a diagram illustrating a connection state of the oil separator and the air
dryer of Fig. 1;
Fig. 3 is a diagram illustrating a mounted state of the oil separator of Fig. 1;
Fig. 4 is a top view illustrating the position of an inlet and an outlet of the oil
separator of Fig. 1;
Fig. 5 is a bottom perspective view illustrating the inside of the lid of the oil
separator of Fig. 1; and
Fig. 6 is a cross-sectional view taken along line 6-6 in Fig. 4.
MODES FOR CARRYING OUT THE INVENTION
[0012] An oil separator according to the present invention will now be described with reference
to Figs. 1 to 5. The oil separator is applied to an exhaust system of an air dryer.
[0013] As shown in Fig. 1, vehicles such as trucks, buses, and construction machines utilize
compressed air delivered by a compressor 1 to control systems such as brakes and suspensions.
Thus, an air dryer 2, which removes oil and water in the compressed air and provides
dried air, is located downstream of the compressor 1 of an air system. The air dryer
2 contains desiccant. The air dryer 2 performs dehumidification to remove oil and
water from the compressed air and regeneration to regenerate the desiccant by removing
the oil and water adsorbed by the desiccant and discharging them to the outside.
[0014] In the present embodiment, since air (purge air) discharged from the air dryer 2
during regeneration of the desiccant includes oil together with water, an oil separator
3 is provided downstream of the compressor 1 of the air system considering the burden
on the environment. In particular, the oil separator 3 is provided in an exhaust system
of the air dryer 2, and separates and recovers the oil and water from purge air discharged
during regeneration of the desiccant in the air dryer 2.
[0015] The oil separator 3 is an impingement plate-type oil separator and includes, inside
the housing, impingement members, against which air containing oil and water strikes.
The impingement plate-type oil separator 3 performs gas/liquid separation by allowing
air containing oil and water to strike the impingement members. In this manner, the
oil separator 3 recovers oil from air, and discharges cleaned air. The separated oil
and water will hereafter be referred to as collected liquid in some cases.
[0016] As shown in Fig. 2, an air dryer 2 includes a cylindrical case 21 having a vertically
upper end closed, and a support member 22, which closes the opening portion of the
case 21 and supports the case 21. A purge air outlet 23, which discharges purge air
during regeneration of a desiccant, is formed at the lower section of the support
member 22. A purge air discharge cover 24 is attached to the purge air outlet 23.
An air dryer connection end of the connecting hose 25 is connected to the purge air
outlet 23 via the purge air discharge cover 24. An oil separator connection end of
the connecting hose 25 is connected to the oil separator 3. The connecting hose 25
is secured to, for example, the chassis of a vehicle with clips 26. An inlet (not
shown) for introducing air compressed by the compressor 1 and an outlet (not shown)
for discharging dried compressed air are formed in the support member 22 of the air
dryer 2.
[0017] The oil separator 3 includes a cylindrical case 31 having a closed end and extending
in the vertical direction and a lid 32, which closes the opening portion of the case
31. The case 31 and the lid 32 form a housing. A drain outlet 33 for draining the
collected liquid that has been stored is provided at a bottom portion 31 a of the
case 31. A drain hose 34, which is used when removing the collected liquid, is connected
to the drain outlet 33. The lid 32 has an inlet 35 for introducing the purge air from
the air dryer 2 through the connecting hose 25, and an outlet 40 for discharging cleaned
air from which oil has been separated. The inlet 35 and the outlet 40 are formed separately.
The oil separator connection end of the connecting hose 25 is connected to the inlet
35 via an coupling member 27. The connecting hose 25 connects the inlet 35 to a connection
port 24a of the purge air discharge cover 24. The angle between the inlet 35 and the
connection port 24a of the purge air discharge cover 24, that is, the angle θ of the
axis along which the connecting hose 25 extends with respect to the horizontal plane
is 40 degrees. The height difference H between the inlet 35 and the connection port
24a of the purge air discharge cover 24 is 700 mm. This maintains discharge of purge
air to the oil separator 3 from the air dryer 2.
[0018] The inlet 35 of the oil separator 3 is located above the connection port of the purge
air discharge cover 24 in the vertical direction. Thus, the overall height of the
installation space, which includes the air dryer 2 and the oil separator 3, is reduced
in the vertical direction.
[0019] An elbow member 41, which extends in the horizontal direction and bends vertically
upward, is connected to the outlet 40 of the oil separator 3. A drip preventing member
42 and a cover 43 for preventing entry of foreign matter are attached on the distal
end of the elbow member 41.
[0020] As shown in Fig. 3, a mounting member 37 is formed integrally with the lid 32 of
the oil separator 3 to extend upright from the lid 32. The mounting member 37 is secured
to a chassis 38 with bolts 39.
[0021] Also, the distal end of the drain hose 34 is hooked to a support plate 44, which
is secured to, for example, the chassis of a vehicle. The distal end of the drain
hose 34 is located above the lid 32 of the oil separator 3.
[0022] As shown in Fig. 4, the lid 32 has the inlet 35 and the outlet 40, which are open
in the same direction. The connecting hose 25 is connected to the inlet 35 via the
coupling member 27. The elbow member 41 is connected to the outlet 40. That is, the
coupling member 27 and the elbow member 41 are arranged next to each other in the
horizontal direction.
[0023] As shown in Fig. 5, the lid 32 is a cylinder having a vertically upper end closed.
Two baffle plates 46 extend from the inner wall of the lid 32 in the vicinity of the
inlet 35 to be perpendicular to the flow direction of the purge air introduced through
the inlet 35. The internal space of the lid 32 functions as a first expansion chamber
45, which expands the purge air introduced from the inlet 35. The lid 32 has a communication
section 32a, which connects the inside of the case 31 to the outlet 40.
[0024] As shown in Fig. 6, a disk-like cover 47, which closes the case 31 and the opening
portion of the lid 32, is provided between the case 31 and the lid 32. The cover 47
and the case 31 are fastened to the lid 32 with bolts 36. That is, the bolts 36 are
fastened to threaded bores formed in a flange portion 32b provided on the lid 32.
Furthermore, threaded portions of the bolts 36 extend through through-holes formed
in a flange portion 31b provided on the case 31. The cover 47 has through-holes through
which the threaded portions of the bolts 36 extend. Thus, the threaded portions of
the bolts 36 extend through the through-holes of the flange portion 31 b of the case
31 and the through-holes of a flange portion 47a of the cover 47. The bolts 36 are
then screwed to the threaded bores of the flange portion 32b of the lid 32 so that
the lid 32, the cover 47, and the case 31 are fastened together. The cover 47 has
a communication hole 47c, which connects the inside of the case 31 to the outlet 40.
[0025] The lid 32 and the cover 47 form a space that functions as the first expansion chamber
45. A cylindrical accommodation member 48 with a vertically upper end closed is secured
to the cover 47 with bolts 36. The accommodation member 48 accommodates a urethane
foam block 50 such as a sponge block. The urethane foam block 50 functions as an impingement
member. A flange portion 48a and a flange portion 48b are formed at an upper edge
and a lower edge of the accommodation member 48, respectively. The bolts 36 extend
through the flange portion 48a formed at the upper edge of the accommodation member
48 so that the accommodation member 48 is tightened to the cover 47. The cover 47
and the upper surface of the accommodation member 48 form a space that functions as
a second expansion chamber 51. The cover 47 has through holes 47b, which connect the
first expansion chamber 45 to the second expansion chamber 51. Through holes 49a are
formed at the center portion of an upper base 49 of the accommodation member 48. The
through holes 47b of the cover 47 and the through holes 49a of the upper base 49 of
the accommodation member 48 are formed at positions that are not opposed to each another.
The accommodation member 48 has through holes 48c formed at the lower end of the side
face at intervals in the radial direction.
[0026] A disk-like support lid 52 is secured with screws 53 to the flange portion 48b,
which is formed at the lower edge of the accommodation member 48. The disk-like support
lid 52 supports the urethane foam block 50 accommodated in the accommodation member
48. The inner diameter of the support lid 52 is substantially the same as the inner
diameter of the case 31. The support lid 52 has through holes 52a, which permit the
oil and water removed by the urethane foam block 50 to drop. Thus, the lower section
in the case 31 functions as a collected liquid storage portion 54. A heater 55 for
evaporating water in the collected liquid by heating the stored collected liquid is
arranged in the collected liquid storage portion 54. Heating of the heater 55 is controlled
by a non-illustrated thermostat.
[0027] The drain hose 34 is transparent, and has a scale 34a corresponding to the volume
of the collected liquid storage portion 54. For example, the scale 34a is provided
corresponding to the upper surface of the collected liquid storage portion 54, the
upper surface of the heater 55, and the lower surface of the collected liquid storage
portion 54. The amount of the collected liquid in the collected liquid storage portion
54 is easily determined by visually checking the amount of the collected liquid in
the drain hose 34.
[0028] Operation of the above-described oil separator will now be described.
[0029] As shown in Fig. 2, the purge air discharged from the air dryer 2 is introduced to
the oil separator 3. The purge air contains oil and water.
[0030] As shown in Fig. 5, the purge air introduced through the inlet 35 strikes the baffle
plates 46, is introduced into the oil separator 3 along the baffle plates 46, and
expands in the first expansion chamber 45.
[0031] As shown in Fig. 6, the air expanded in the first expansion chamber 45 enters the
second expansion chamber 51 via the through holes 47b formed in the cover 47. The
air that has expanded in the second expansion chamber 51 enters the accommodation
member 48 via the through holes 49a of the upper base 49 of the accommodation member
48. At this time, the oil and water that has struck the urethane foam block 50 is
separated from the air. The liquid that contains the water and the oil trapped by
the urethane foam block 50 moves through the urethane foam block 50. The liquid reaches
the upper surface of the support lid 52, drops from the through holes 52a of the support
lid 52 into a collected liquid storage portion 54, and is stored in the collected
liquid storage portion 54. The collected liquid that has stored in the collected liquid
storage portion 54 enters the drain hose 34 through the drain outlet 33. The collected
liquid stored in the collected liquid storage portion 54 is heated by the heater 55.
This evaporates the water in the collected liquid. Furthermore, the amount of the
collected liquid stored in the collected liquid storage portion 54 can be grasped
by checking the amount of the collected liquid stored in the drain hose 34. When the
amount of the collected liquid approaches the upper limit, the collected liquid is
drained from the collected liquid storage portion 54 through the drain hose 34.
[0032] On the other hand, oil and water are separated from the air that has entered the
accommodation member 48 from the through holes 49a of the upper base 49 of the accommodation
member 48. The air then enters the case 31 from the through holes 48c on the side
face of the accommodation member 48. The air that has entered the case 31 passes through
the communication hole 47c of the cover 47 and the communication section 32a of the
lid 32, and is discharged through the outlet 40. Thus, the air that has entered the
case 31 hardly contacts the collected liquid in the collected liquid storage portion
54, and is discharged from the outlet 40. The air that is discharged from the outlet
40 is cleaned air that does not contain oil.
[0033] The above-described embodiment achieves the following advantages.
- (1) When the connecting hose 25 connects the inlet 35 to the connection port 24a of
the purge air discharge cover 24, the inlet 35 is located at a higher position than
the connection port 24a of the purge air discharge cover 24 in the vertical direction.
That is, the inlet 35 of the oil separator 3 is located above the connection port
24a of the purge air discharge cover 24 in the vertical direction. This reduces the
heights of the air dryer 2 and the oil separator 3, that is, the height of the installation
space of the air dryer 2 and the oil separator 3 in the vertical direction.
- (2) When the connecting hose 25 connects the inlet 35 to the connection port 24a of
the purge air discharge cover 24, the angle between the inlet 35 and the connection
port 24a of the purge air discharge cover 24, that is, the angle θ of the axis along
which the connecting hose 25 extends with respect to the horizontal plane is less
than or equal to 40 degrees, and the height difference H between the inlet 35 and
the connection port 24a of the purge air discharge cover 24 is less than or equal
to 700 mm. This reduces the heights in the vertical direction of the air dryer 2 and
the oil separator 3, while maintaining discharge of purge air to the oil separator
3 from the air dryer 2.
[0034] The above described embodiment may be modified as follows.
[0035] · In the above illustrated embodiment, when the connecting hose 25 connects the inlet
35 to the connection port 24a of the purge air discharge cover 24, the angle θ between
the inlet 35 and the connection port 24a of the purge air discharge cover 24 may be
greater than 40 degrees and less than or equal to 45 degrees, and the height difference
H between the inlet 35 and the connection port 24a of the purge air discharge cover
24 may be greater than 700 mm and less than or equal to 1000 mm.
[0036] In the above illustrated embodiment, the scale 34a is provided on the drain hose
34, but the scale 34a may be omitted from the drain hose 34.
[0037] · In the above illustrated embodiment, the drain hose 34 is connected to the drain
outlet 33 of the case 31. However, the drain hose 34 may be omitted, and a plug may
be provided on the drain outlet 33 so that the collected liquid can be directly discharged
from the drain outlet 33.
[0038] · In the above illustrated embodiment, the first expansion chamber 45 and the second
expansion chamber 51 are provided in the oil separator 3. However, at least one of
the first expansion chamber 45 and the second expansion chamber 51 may be provided.
[0039] · In the above illustrated embodiment, a member such as a nonwoven fabric filter
may be provided upstream or downstream of the urethane foam block 50 or in the expansion
chambers 45, 46. In this case, the removal rate of the oil component is increased.
Furthermore, the urethane foam block 50 such as a sponge block or a member such as
a nonwoven fabric filter may be charged with static electricity. The members can be
charged with static electricity by a method such as utilizing the flow of dried air
from the dryer. Also, the urethane foam block 50 such as a sponge block and the member
such as a nonwoven fabric filter may be formed of material that is electrically charged
from the beginning. In this case, the removal rate of the oil component is further
increased.
[0040] · In above illustrated third embodiment, the urethane foam block 50 is employed as
the impingement member, but other members such as a crushed aluminum member may be
employed. Furthermore, instead of an expansion chamber having an impingement member,
a simple expansion chamber without any impingement member may be employed.
[0041] · In the above illustrated embodiment, the number of heater 55 may be changed as
required.
1. An oil separator comprising:
a housing including an inlet for air and an outlet for air;
an expansion chamber, which is located in the housing and expands air that has been
introduced through the inlet;
an accommodation member, which is located in the housing and communicates with the
expansion chamber in the vertical direction, wherein the accommodation member accommodates
an impingement member; and
a collected liquid storage portion located below the accommodation member, wherein
the oil separator introduces air containing oil from an air dryer into the housing
through the inlet and causes the air to strike the impingement member to separate
oil from the introduced air, thereby recovering the oil,
the inlet and the outlet are located in an upper section of the housing,
the oil separator further includes a connecting hose having an oil separator connection
end for being connected to the inlet and an air dryer connection end for being connected
to a purge air outlet, which discharges purge air from the air dryer, and
the connecting hose is configured such that when the connecting hose connects the
inlet to the purge air outlet, the oil separator connection end is located at a position
higher than the air dryer connection end in the vertical direction.
2. The oil separator according to claim 1, wherein
the housing includes a case having an opening portion and a lid that closes the opening
portion,
the inlet and the outlet are located in the lid, and
the lid has a communication section that connects the case and the outlet to each
other.
3. The oil separator according to claim 1 or 2, wherein the accommodation member is configured
to discharge sideways the air that has entered from the expansion chamber.
4. The oil separator according to any one of claims 1 to 3, wherein,
an angle of an axis along which the connecting hose extends with respect to a horizontal
plane is less than or equal to 45 degrees, and
a height difference between the oil separator connection end and the air dryer connection
end is less than or equal to 1000 mm.
5. The oil separator according to any one of claims 1 to 4, wherein,
an angle of an axis along which the connecting hose extends with respect to a horizontal
plane is less than or equal to 40 degrees, and
a height difference between the oil separator connection end and the air dryer connection
end is less than or equal to 700 mm.